{
  "id": "2303.16234",
  "version": "v1",
  "published": "2023-03-28T18:06:08.000Z",
  "updated": "2023-03-28T18:06:08.000Z",
  "title": "Probing the Star Formation Main Sequence down to $10^{8}$ M$_\\odot$ at $1.0<z<3.0$",
  "authors": [
    "Rosa M. Mérida",
    "Pablo G. Pérez-González",
    "Patricia Sánchez-Blázquez",
    "Ángela García-Argumánez",
    "Marianna Annunziatella",
    "Luca Costantin",
    "Alejandro Lumbreras-Calle",
    "Belén Alcalde-Pampliega",
    "Guillermo Barro",
    "Néstor Espino-Briones",
    "Anton M. Koekemoer"
  ],
  "comment": "34 pages, 16 figures, 9 tables. Accepted for publication to ApJ",
  "categories": [
    "astro-ph.GA"
  ],
  "abstract": "We investigate the star formation main sequence (MS) (SFR-M$_{\\star}$) down to 10$^{8-9}\\mathrm{M}_\\odot$ using a sample of 34,061 newly-discovered ultra-faint ($27\\lesssim i \\lesssim 30$ mag) galaxies at $1<z<3$ detected in the GOODS-N field. Virtually these galaxies are not contained in previous public catalogs, effectively doubling the number of known sources in the field. The sample was constructed by stacking the optical broad-band observations taken by the HST/GOODS-CANDELS surveys as well as the 25 ultra-deep medium-band images gathered by the GTC/SHARDS project. Our sources are faint (average observed magnitudes $<i>\\sim28.2$ mag, $<H>\\sim27.9$ mag), blue (UV-slope $<\\beta>\\sim-1.9$), star-forming (rest-frame colors $<U-V>\\sim0.10$ mag, $<V-J>\\sim0.17$ mag) galaxies. These observational characteristics are identified with young (mass-weighted age $<\\mathrm{t_{M-w}}>\\sim0.014$ Gyr) stellar populations subject to low attenuations ($<\\mathrm{A(V)}>\\sim0.30$ mag). Our sample allows us to probe the MS down to $10^{8.0}\\,\\mathrm{M}_\\odot$ at $z=1$ and $10^{8.5}\\,\\mathrm{M}_\\odot$ at $z=3$, around 0.6 dex deeper than previous analysis. In the low-mass galaxy regime, we find an average value for the slope of 0.97 at $1<z<2$ and 1.12 at $2<z<3$. Nearly $\\sim$60% of our sample presents stellar masses in the range $10^{6-8}$ M$_\\odot$ between $1<z<3$. If the slope of the MS remained constant in this regime, the sources populating the low-mass tail of our sample would qualify as starburst galaxies.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2023-03-28T18:06:08.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "star formation main sequence",
      "optical broad-band observations taken",
      "low-mass galaxy regime",
      "ultra-deep medium-band images",
      "stellar populations subject"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 34,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}